Loose bulk materials such as sand, gravel, dry premix concrete, pelletized plastics, and even foodstuffs such as grains and the like, are often packaged in soft containers such as fabric bags. However, some bulk materials are not suited for storage in porous containers due to the susceptibility of the bulk materials to spoilage, chemical reactivity, or other adverse effects. For example, dry premix concrete (i.e. a dry mixture of cement binder and one or more of sand, gravel, and/or natural or man-made aggregate) cannot be stored in porous packaging materials, such as fabric or paper, unless the packages are kept in dry environments, because the cement binder component of the premix concrete can react with environmental moisture and harden prematurely.